When we talk of battles and wars in a Christian life, it is almost always about the battle inside us that takes place when a sinful thought tempts us to do sin. God’s Spirit and our own sinful human nature, also called the flesh, are in conflict with one another. When you have decided to only do God’s will and you are being led by the Spirit, there comes a conflict between the flesh and the Spirit: this is a battle where you must overcome the temptation and overcome that sin. (Galatians 5:16-17; Hebrews 12:4.)